Composition and method to polish silicon nitride

Abstract

The inventive chemical-mechanical polishing composition comprises an abrasive, a nitride accelerator, and water, and has a pH of about 1 to about 6. The inventive method of polishing a substrate involves the use of the aforesaid polishing composition and is particularly useful in polishing a substrate containing silicon nitride.

1 . A chemical-mechanical polishing composition comprising: 
 (a) an abrasive,    (b) about 0.1 mM to about 10 mM malonic acid,    (c) about 0.1 mM to about 100 mM of an aminocarboxylic acid,    (d) about 0.1 mM to about 100 mM sulfate ion, and    (e) water,    wherein the polishing composition has a pH of about 1 to about 6.    
   
   
       2 . The polishing composition of  claim 1 , wherein the abrasive is condensation-polymerized silica.  
   
   
       3 . The polishing composition of  claim 2 , wherein the condensation-polymerized silica is present in the amount of about 0.5 wt. % to about 10 wt. %.  
   
   
       4 . The polishing composition of  claim 1 , wherein the aminocarboxylic acid is glycine.  
   
   
       5 . The polishing composition of  claim 4 , wherein the glycine is present at a concentration of about 10 mM to about 30 mM.  
   
   
       6 . The polishing composition of  claim 1 , wherein the sulfate ion is present at a concentration of about 2.5 mM to about 25 mM.  
   
   
       7 . The polishing composition of  claim 1 , wherein the polishing composition has a pH of about 2 to about 4.  
   
   
       8 . A chemical-mechanical polishing system comprising a polishing pad and the polishing composition of  claim 1 .  
   
   
       9 . A chemical-mechanical polishing composition comprising: 
 (a) an abrasive,    (b) about 0.1 mM to about 25 mM of an organic acid selected from the group consisting of aryldicarboxylic acids, phenylacetic acids, and combinations thereof, and    (c) water,    wherein the polishing composition has a pH of about 1 to about 6.    
   
   
       10 . The polishing composition of  claim 9 , wherein the abrasive is condensation-polymerized silica.  
   
   
       11 . The polishing composition of  claim 9 , wherein the aryldicarboxylic acid is phthalic acid.  
   
   
       12 . The polishing composition of  claim 9 , wherein the phenylacetic acid is mandelic acid.  
   
   
       13 . The polishing composition of  claim 9 , wherein the organic acid is a combination of phthalic acid and mandelic acid.  
   
   
       14 . The polishing composition of  claim 9 , wherein the polishing composition has a pH of about 2 to about 4.  
   
   
       15 . A chemical-mechanical polishing system comprising a polishing pad and the polishing composition of  claim 9 .  
   
   
       16 . A chemical-mechanical polishing composition comprising: 
 (a) an abrasive,    (b) about 0.001 mM to about 100 mM of potassium stannate, and    (c) water,    wherein the polishing composition has a pH of about 1 to about 6.    
   
   
       17 . The polishing composition of  claim 16 , wherein the abrasive is condensation-polymerized silica.  
   
   
       18 . The polishing composition of  claim 16 , wherein the potassium stannate is present at a concentration of about 0.1 mM to about 10 mM.  
   
   
       19 . The polishing composition of  claim 16 , wherein the polishing composition has a pH of about 2 to about 4.  
   
   
       20 . A chemical-mechanical polishing system comprising a polishing pad and the polishing composition of  claim 16 .  
   
   
       21 . A chemical-mechanical polishing composition comprising: 
 (a) an abrasive,    (b) about 0.001 wt. % to about 1 wt. % uric acid, and    (c) water,    wherein the polishing composition has a pH of about 1 to about 6.    
   
   
       22 . The polishing composition of  claim 21 , wherein the abrasive is condensation-polymerized silica.  
   
   
       23 . The polishing composition of  claim 21 , wherein the uric acid is present in an amount of about 0.01 wt. % to about 0.5 wt. %.  
   
   
       24 . The polishing composition of  claim 21 , wherein the polishing composition has a pH of about 2 to about 4.  
   
   
       25 . A chemical-mechanical polishing system comprising a polishing pad and the polishing composition of  claim 21 .  
   
   
       26 . A method for chemically-mechanically polishing a substrate, which method comprises: 
 (i) contacting a substrate comprising silicon nitride and silicon oxide with a polishing pad and the polishing composition of  claim 1 ,    (ii) moving the polishing pad relative to the substrate, and    (iii) abrading at least a portion of the substrate to polish the substrate.    
   
   
       27 . The method of  claim 26 , wherein the abrasive is condensation-polymerized silica.  
   
   
       28 . The method of  claim 27 , wherein the condensation-polymerized silica is present in the amount of about 0.5 wt. % to about 10 wt. %.  
   
   
       29 . The method of  claim 26 , wherein the aminocarboxylic acid is glycine  
   
   
       30 . The method of  claim 29 , wherein the glycine is present at a concentration of about 10 mM to about 30 mM.  
   
   
       31 . The method of  claim 26 , wherein the sulfate ion is present at a concentration of about 2.5 mM to about 25 mM.  
   
   
       32 . The method of  claim 26 , wherein the polishing composition has a pH of about 2 to about 4.  
   
   
       33 . A method for chemically-mechanically polishing a substrate, which method comprises: 
 (i) contacting a substrate comprising silicon nitride and silicon oxide with a polishing pad and the polishing composition of  claim 9 ,    (ii) moving the polishing pad relative to the substrate, and    (iii) abrading at least a portion of the substrate to polish the substrate.    
   
   
       34 . The method of  claim 33 , wherein the abrasive is condensation-polymerized silica.  
   
   
       35 . The method of  claim 33 , wherein the aryldicarboxylic acid is phthalic acid.  
   
   
       36 . The method of  claim 33 , wherein the phenylacetic acid is mandelic acid.  
   
   
       37 . The method of  claim 33 , wherein the organic acid is a combination of phthalic acid and mandelic acid.  
   
   
       38 . The method of  claim 33 , wherein the polishing composition has a pH of about 2 to about 4.  
   
   
       39 . A method for chemically-mechanically polishing a substrate, which method comprises: 
 (i) contacting a substrate comprising silicon nitride and silicon oxide with a polishing pad and the polishing composition of  claim 16 ,    (ii) moving the polishing pad relative to the substrate, and    (iii) abrading at least a portion of the substrate to polish the substrate.    
   
   
       40 . The method of  claim 39 , wherein the abrasive is condensation-polymerized silica.  
   
   
       41 . The method of  claim 39 , wherein the potassium stannate is present at a concentration of about 0.1 mM to about 10 mM.  
   
   
       42 . The method of  claim 39 , wherein the polishing composition has a pH of about 2 to about 4.  
   
   
       43 . A method for chemically-mechanically polishing a substrate, which method comprises: 
 (i) contacting a substrate comprising silicon nitride and silicon oxide with a polishing pad and the polishing composition of  claim 21 ,    (ii) moving the polishing pad relative to the substrate, and    (iii) abrading at least a portion of the substrate to polish the substrate.    
   
   
       44 . The method of  claim 43 , wherein the abrasive is condensation-polymerized silica.  
   
   
       45 . The method of  claim 43 , wherein the uric acid is present in an amount of about 0.01 wt. % to about 0.5 wt. %.  
   
   
       46 . The method of  claim 43 , wherein the polishing composition has a pH of about 2 to about 4.